Were you around during the 1990s dotcom boom? Then you ought to know the name Dan Wagner.

Wagner was famed for insisting on wearing a Donald Duck waistcoat as much as for his achievement of becoming a chief executive of a public company in his 20s, and for a confrontational reputation while presiding over a firm whose shares crashed by 95%.

"I had quite a lot of coverage, not all welcome," admits the former boss of Dialog, the technology company that City wags renamed Dial-a-dog. "It was partly because I spoke my mind, which is not always a good trait in a public company chief executive."

Now he's back – at least back trying to get into financiers' good books – and dressed in a sober suit and slicked back hair, the 48-year-old suddenly looks far more City-like. "I have been 10 years in the private [company] sector," he adds. "It feels like about the right time to come back out again."

The reason, obviously, is he has something to sell. That something is his e-commerce business Venda, built from the technology that Wagner bought for £250,000 out of the ashes of one of the most famous dotcom busts of all – fashion retailer Boo.com. The entrepreneur holds a near 30% stake and Venda is up for sale, either via a flotation or to a trade buyer. Mind you, that has been true for years.

In 2008 Venda recruited former Orange and Wanadoo executive Eric Abensur and said it would float. It didn't. "The whole world changed," Wagner protests, before switching back to the script. "Venda is doing well in the US. It is a good thing for Britain. This is a buyers' market. We may not do anything. We are not desperate. We don't need to sell."

It is a convincing piece of sales patter, which probably disguises what a slog it's been to get this far. Venda's last accounts show the company lost £5.1m before tax in the year to June 2010, an improvement on the previous year when it lost £7.3m. About 23% of the group's £10.5m revenues came from the US, and there is a caveat to Wagner's cool "don't need to sell" line.

Two months ago the company raised $2.25m (£1.4m) issuing 5.5m new preference shares to existing investors. The documents, dated 15 September 2011, state: "If the company has not completed a qualified IPO or effected a liquidation event one year after issue of [the new shares], then the holders of the [new shares] are entitled to receive a compounding dividend of 10% per annum."

So why pay so much for so little cash? The money has been raised to promote the company in the US, where Venda has just won a contract to supply Fort Knox that will be worth $6m in the first year (and possibly a lot more afterwards).

The high interest rate, Wagner says, will provide the company with an "incentive" to sell by September. But as existing shareholders are putting up the funds, it suggests somebody is very keen to cash out. Did Wagner push for the high rate? He won't say.

He may just want to move on and even talks of a sensational return to the public markets by putting his other businesses into a holding company and floating that.

The new projects are all internet-focused. There is Locayta, which profiles visitors to websites; Powa, that allows businesses to quickly and securely deploy hundreds of e-commerce sites; Buya Powa, a group buying start-up; and Aigua, a fashion blog publishing company.

"Everything I have has got an A on the end," Wagner says. "I'm thinking of changing my name by deed poll to Dan Wagna." Now, even his City detractors must concede that's not such a bad joke.